Typical dental x-rays are performed with an x-ray source or an x-ray receiver disposed outside the mouth of a patient, and the other of the x-ray source or x-ray receiver disposed inside the mouth of the patient. The patient's cheek or lip may force a gap between source or receiver and the tooth. Because of this gap, increased x-ray flux may be needed to obtain an image of the tooth. The cheek or lip may also block the medical professional's view, resulting in images taken at incorrect locations. As a result, the x-ray image may need to be retaken. Increased x-ray flux due to the large gap and due to retakes of the image may expose the patient to extra, undesirable radiation, which can cause health problems. For example, see Korean Patent Number KR 10-1147059 and U.S. Pat. Nos. 3,752,990, 3,906,235, 4,100,417, 4,193,002.